A catheter for introduction into a blood vessel is used mainly for injection of a medical solution, a contrast media, etc. into the blood vessel for the treatment or inspection of a diseased portion within the blood vessel. The conventional catheter of this type is constructed such that a hub is simply mounted to the proximal end of a flexible tubular body. For introducing the conventional catheter into a blood vessel, a guide wire is inserted in advance into the blood vessel, followed by introducing the catheter into a desired position within the blood vessel along the guide wire.
The requirement of guiding by a guide wire necessitates a troublesome operation for a long time for enabling the distal end of the conventional catheter to reach a desired position. Also, a blood vessel after branching is bent and diminished in inner diameter, leading to an increased resistance to the catheter insertion. Naturally, it is difficult to insert a guide wire into the branched blood vessel, making it more difficult to introduce the catheter to reach the desired position. Further, a series of operations for insertion and withdrawal of the catheter give serious pains to the patient.
An object of the present invention is to provide a catheter for introduction into a blood vessel, which can be easily introduced even into a branched blood vessel such as a celiac artery without using a guide wire. The catheter of the present invention permits markedly alleviating the pain given to the patient. Also, it is possible to simplify the operation for introducing the catheter into a blood vessel.